Propellant powder charge



Patented June 11, 1929.

UNITED STATES PATENT OFFICE,

JOHN ."B. FIDLAR, OF THE 'I J'NITED STATES ARMY, OF DOVER, NEW JERSEY.

PROPELLANT POWDER CHARGE.

No Drawing.

Application filed December 5, 1921; Serial No. 520,130.

(GRANTED UNDER THE ACT or MARCH 3, 1883, AS AMENDED APRIL so, 1928; 370 o. a. 757.

are: the provision of a flashless, non-hygroscopic propellant powder which may be prepared in such form that the propellant charge container usually used with a trench mortar bomb may be eliminated, and also that with the same elevation of the mortar greater flexibility of range may be secured.

Further objects of the invention will appear as the description proceeds.

Inthe usual trench mortar home a black powder cartridge, preferably of 12 gauge, is fitted in the shell container. Former practice has been to provide a propellant charge consisting either of silk rings filled with cordite or nitrotit-e (a modified cellulose) rings filled with ballistite. These rings are fitted over the shell container and are ignited by the powder charge in the blank cartridge which flashes through the apertures in the container.

The present form of propellant consists of a number of thin disks the centers of which are stamped out to enable the rings to he slipped over the shell container, the remaining annular sheet is perforated with numerous small holes of suitable spacing and dimensions to insure the desired rate of burning. This form of grain or disc is also suitable for use with the British type of bomb in which instance the rings are placed in the powder receptacle over the detonator. The grain or disc is preferably obtained by rolling the previously mixed ingredients into sheets between hot rolls until the proper thickness to give the required ballistic results has been secured. The grains are then stamped out from these sheets by means of dies.

The powder from which the grains or discs are formed is composed of nitrocellulose, nitroglycerine and nitro aromatic hydrocarbons. To this mixture may be added, if desired, any suitable stabilizer but I prefer to use diphenylamiue as the reagent. It has also been found desirable to include as an ingredient of this mixture a flame reducing element or elements to the end thatthe flash given off upon firing the mortar may be reduced to such an extent as to be invisible at a distance of a few hundred yards.

From the foregoing it is evident that my invention consists in forming a compound of nitrocellulose, nitroglycerine' and nitrated aromatic hydrocarbons to which may be added, if desired, a stabilizing reagent and a flame reducing element or elements and a subsequent treatment of such mixture to form the same into grains or discs. By Way of example the following mixtures or ingredient's are submitted.

Nitrocellulose 40 plus or minus 5 parts, Nitroglycerine 20 plus or minus 5 parts. 'Dinitro aromatic hydrocarbons 10 plus or minus 5 parts.

or minus 5 parts.

.- Di-phenylamine 1.1 plus or minus 1 part.

The dinit-ro-aromatic hydrocarbon is usually, but not necessarily dinitrotoluene, and the trinitro aromatic hydrocarbon is preferably but not necessarily trinitrotoluene.

The above composition is non-hygroscopic and gives considerably less flash than the cordite or the ballistite usually employed. This mixture may, however, be modified so that on firing only a few sparks or a dull red ball of flame hardly visible at a few hundred yards results by replacing up to 10% nitro aromatic hydrocarbon with a flame reducing element such as corn starch or black powder ingredients or both.

- A successful flashless powder of this type has the composition Parts. Nitrocellulose- 35 N itroglycerine 25 Dinitrotoluene 5 Trinitrotoluene 2O Cornstarch 5 Black powder ingredients 5 The addition of cornstarch tends to make the powder more difiicult to work between the rolls on accountof the reduction in plasticity. The cornstarch increases the hygroscopicity. These deleterious defects maybe overcome by increasing the nitroglycerine content and a highly satisfactory fiashless than the old silk or celluloid rings, 0 non-hygroscopic propellant has been formed four of which could-be used, will permi from the following mgredients: greater range of propellant charge as m c Nitrocellulose 30 plus or minus 5 parts. or less rings may he placed upon the car- I Nitroglycerine 35 plus or minus 5 parts. tridge container and so secure a more flex- Star ch 15 plus or minus 5 parts. ible range without changing the elevation of Black powder ingredients 5 plus or minus the mortar. 5 parts. I I claim;

Nitro aromatic hydrocarbons 15 plus or A propellant powder including nitrocel- 10 minus 5'parts. lulose 35 parts, nitroglycerine 25 parts, It is evident that the discs of. powder dinitrotoluene 5 parts, trinitrotoluene 20 formed 'from the compositions above set parts and flame reducing materials. 10 parts. forth, being thinner and less cumbersome JOHN B. FIDLAR. 

